The invention relates to removing condensate from air conditioning systems.
Air conditioning systems generally include a blower which blows or draws air over a heat exchanger coil on which condensation accumulates and drips to a discharge pan positioned below the coil. The condensation (or condensate) which overflows from the pan is drained from the system through a discharge port on to the ground or into the sewer system.
Referring to FIG. 1A, an air conditioning system 10 includes a blower 11 positioned to draw external air through a filter 14 and push the air over a heat exchanger 12, thereby presenting positive pressure at the discharge port where the condensate is discharged. A system having the blower positioned with respect to the heat exchanger in this manner is known as a "blow-through" system. Condensate from the heat exchanger drips into a condensate pan 13 having a drain port 15 connected to a U-shaped condensate trap 16.
Referring to FIG. 1B, on the other hand, if the blower is positioned to draw air over the coil, the system is a "draw-through" system with a negative pressure present at the port where the condensate is discharged. With this arrangement, blower 11 is positioned to pull air through the heat exchanger.
A condensate trap 16 in the form of U-shaped piping is generally provided at the discharge port. In either configuration, the U-shaped trap 16 must be filled with water prior to starting up the system. The water in the trap forms a barrier between atmospheric pressure at the discharge port of the trap and the pressure level within the system, thereby preventing escape of conditioned air in the system of FIG. 1A or introducing outside air into the system of FIG. 1B. The trap also collects foreign material passed through the discharge pan from the system.